Vehicle control device, vehicle control method, and storage medium

ABSTRACT

A vehicle control device according to an embodiment includes a recognizer that recognizes a surroundings situation of a host vehicle, and a driving controller that generates a target trajectory for the host vehicle on the basis of a recognition result of the recognizer, and controls one or both of speed and steering of the host vehicle so that the host vehicle travels along the generated target trajectory, the recognizer searches for, in a branch section in which a main lane and a plurality of branch lanes are connected, a number-of-lanes increase end position satisfying a predetermined condition on the start position side of the branch section, rather than an end position of the branch section, and the driving controller generates the target trajectory so that course change to the branch lane is completed until the host vehicle reaches the number-of-lanes increase end position.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed on Japanese Patent Application No. 2022-053468,filed on Mar. 29, 2022, the content of which is incorporated herein byreference.

BACKGROUND Field of the Invention

The present invention relates to a vehicle control device, a vehiclecontrol method, and a storage medium.

Description of Related Art

In the related art, a technology for recognizing a road demarcation linethat demarcates a lane in which a vehicle is traveling, generating atarget trajectory with reference to the recognized demarcation line, andcausing the vehicle to automatically travel along the generated targettrajectory is known (for example, Japanese Unexamined PatentApplication, First Publication No 2020-126024).

SUMMARY

However, since a demarcation line demarcating a main lane and a branchlane branching from the main lane may not be present in a branch sectionin which there are the main lane and the branch lane, an appropriatetarget trajectory may not be able to be generated and appropriatevehicle driving control may not be performed.

Aspects of the present invention have been made in consideration of suchcircumstances, and one object thereof is to provide a vehicle controldevice, a vehicle control method, and a storage medium capable ofperforming more appropriate driving control in a branch section.

A vehicle control device, vehicle control method, and storage mediumaccording to the present invention adopt the following configurations.

-   -   (1): A vehicle control device according to an aspect of the        present invention is a vehicle control device including: a        recognizer configured to recognize a surroundings situation of a        host vehicle on the basis of information obtained from at least        one of a detection device and map information; and a driving        controller configured to generate a target trajectory for the        host vehicle on the basis of a recognition result of the        recognizer, and control one or both of speed and steering of the        host vehicle so that the host vehicle travels along the        generated target trajectory, wherein the recognizer searches        for, in a branch section in which a main lane and a plurality of        branch lanes are connected, a number-of-lanes increase end        position satisfying a predetermined condition on the start        position side of the branch section, rather than an end position        of the branch section, and the driving controller generates the        target trajectory so that course change to the branch lane is        completed until the host vehicle reaches the number-of-lanes        increase end position.    -   (2): In the aspect (1), the recognizer makes a search direction        for the number-of-lanes increase end position and the        predetermined condition different, on the basis of a search        start position at which a search for the number-of-lanes        increase end position starts and an edge position of the branch        lane connected to the branch section.    -   (3): In the aspect (2), the edge position of the branch lane is        a position at which a road width in the branch section is        maximized, and the search start position is on the start        position side of the branch section rather than the edge        position of the branch lane, the recognizer searches for a        number-of-lanes increase end position toward the edge position        of the branch lane from the search start position, and sets a        position at which a road width is within a predetermined error        range with respect to the road width as the number-of-lanes        increase end position.    -   (4): In the aspect (2), when the edge position of the branch        lane is present on the start position side of the branch section        rather than the end position of the branch section, the        recognizer sets the edge position of the branch lane as the        search start position to search for the number-of-lanes increase        end position toward the start position of the branch section,        and sets a position at which a road width is larger than a        predetermined error range with respect to a road width at the        edge position of the branch lane as the number-of-lanes increase        end position.    -   (5): In the aspect (2), the search start position is determined        on the basis of a position of a soft nose in the branch section.    -   (6): In the aspect (1), the recognizer searches for a        number-of-lanes increase start position in the branch section,        and the driving controller generates the target trajectory so        that the target trajectory passes through the number-of-lanes        increase start position and reaches the branch lane.    -   (7): In the aspect (6), the number-of-lanes increase start        position is a position at which a degree of interference between        a demarcation line in the branch section and the target        trajectory is low.    -   (8): A vehicle control method according to an aspect of the        present invention is a vehicle control method including:        recognizing, by a computer, a surroundings situation of a host        vehicle on the basis of information obtained from at least one        of a detection device and map information; generating, by the        computer, a target trajectory for the host vehicle on the basis        of a recognition result, and executing driving control for        controlling one or both of speed and steering of the host        vehicle so that the host vehicle travels along the generated        target trajectory; searching for, by the computer, in a branch        section in which a main lane and a plurality of branch lanes are        connected, a number-of-lanes increase end position satisfying a        predetermined condition on the start position side of the branch        section, rather than an end position of the branch section; and        generating, by the computer, the target trajectory so that        course change to the branch lane is completed until the host        vehicle reaches the number-of-lanes increase end position.    -   (9): A storage medium according to an aspect of the present        invention is a computer-readable non-transitory storage medium        having a program stored therein, the program causing a computer        to: recognize a surroundings situation of a host vehicle on the        basis of information obtained from at least one of a detection        device and map information; generate a target trajectory for the        host vehicle on the basis of a recognition result, and execute        driving control for controlling one or both of speed and        steering of the host vehicle so that the host vehicle travels        along the generated target trajectory; search for, in a branch        section in which a main lane and a plurality of branch lanes are        connected, a number-of-lanes increase end position satisfying a        predetermined condition on the start position side of the branch        section, rather than an end position of the branch section; and        generate the target trajectory so that course change to the        branch lane is completed until the host vehicle reaches the        number-of-lanes increase end position.

According to the aspects (1) to (9), it is possible to perform moreappropriate driving control in the branch section.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an example of a configuration of a vehiclesystem on which a vehicle control device is mounted according to a firstembodiment.

FIG. 2 is a functional configuration diagram of a first controller and asecond controller.

FIG. 3 is a diagram showing an example of functional configurations of arecognizer, a determiner, and an action plan generator.

FIG. 4 is a diagram for describing a function of a virtual demarcationline setter.

FIG. 5 is a diagram showing an example of setting a virtual demarcationline when there are a plurality of branch section end points.

FIG. 6 is a diagram for describing generation of a target trajectorywhen lane change is performed in a branch section.

FIG. 7 is a flowchart showing an example of a flow of driving controlprocessing executed by the automated driving control device of the firstembodiment.

FIG. 8 is a flowchart showing an example of processing for estimating abranch lane shape in the first embodiment.

FIG. 9 is a diagram for describing a method of searching for anumber-of-lanes increase start position of a branch lane in a secondembodiment.

FIG. 10 is a flowchart showing an example of processing for estimating abranch lane shape in the second embodiment.

FIG. 11 is a diagram for describing a method of determining anumber-of-lanes increase end position in a first road shape pattern.

FIG. 12 is a diagram for describing a number-of-lanes increase endposition determined in the first road shape pattern.

FIG. 13 is a diagram for describing a method of determining anumber-of-lanes increase end position in a second road shape pattern.

FIG. 14 is a flow chart showing an example of processing for estimatinga branch lane shape according to a third embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of a vehicle control device, a vehicle controlmethod, and a storage medium of the present invention will be describedwith reference to the drawings. Hereinafter, an embodiment in which thevehicle control device is applied to an automated driving vehicle willbe described by way of example. The automated driving is, for example,to automatically control one or both of steering and acceleration ordeceleration of a vehicle to execute driving control. Examples of thedriving control of the vehicle may include various driving assistancesuch as lane keeping assistance system (LKAS), adaptive cruise control(ACC), and auto lane changing (ALC). The automated driving vehicle maybe a vehicle whose driving is partially or wholly controlled by manualdriving of an occupant (driver). Hereinafter, a case in which aleft-hand traffic regulation is applied will be described, but right andleft may be reversed when a right-hand traffic regulation is applied.

First Embodiment [Overall Configuration]

FIG. 1 is a diagram showing an example of a configuration of a vehiclesystem 1 on which a vehicle control device is mounted according to afirst embodiment. A vehicle on which the vehicle system 1 is mounted(hereinafter referred to as a host vehicle M) is, for example, a vehiclesuch as a two-wheeled vehicle, a three-wheeled vehicle, or afour-wheeled vehicle, and a driving source thereof includes an internalcombustion engine such as a diesel engine or a gasoline engine, anelectric motor, or a combination thereof. The electric motor operatesusing power generated by a power generator connected to the internalcombustion engine or discharge power of a secondary battery or a fuelcell.

The vehicle system 1 includes, for example, a camera 10, a radar device12, a light detection and ranging (LIDAR) 14, an object recognitiondevice 16, a communication device 20, a human machine interface (HMI)30, a vehicle sensor 40, a navigation device 50, a map positioning unit(MPU) 60, a driving operator 80, an automated driving control device100, a travel driving force output device 200, a brake device 210, and asteering device 220. These devices or equipment are connected to eachother by a multiplex communication line such as a controller areanetwork (CAN) communication line, a serial communication line, awireless communication network, or the like. The configuration shown inFIG. 1 is merely an example, and a part of the configuration may beomitted or other configurations may be added thereto. The automateddriving control device 100 is an example of a “vehicle control device”.A combination of the camera 10, the radar device 12, the LIDAR 14, andthe object recognition device 16 is an example of a “detection deviceDD”. The HMI 30 is an example of an “output device”.

The camera 10 is, for example, a digital camera using a solid-stateimaging device such as a charge coupled device (CCD) or a complementarymetal oxide semiconductor (CMOS). The camera 10 is attached to anylocation on a host vehicle M. When a forward side is imaged, the camera10 is attached to, for example, an upper portion of a front windshield,a rear surface of a rearview mirror, or the like. When a backward sideof the host vehicle M is imaged, the camera 10 is attached to an upperportion of a rear windshield, a back door, or the like. When a sidewardside and a rear sideward side of the host vehicle M are imaged, thecamera 10 is attached to a door mirror or the like. The camera 10, forexample, periodically and repeatedly images surroundings of the hostvehicle M. The camera 10 may be a stereo camera.

The radar device 12 radiates radio waves such as millimeter waves to thesurroundings of the host vehicle M and detects radio waves (reflectedwaves) reflected by an object to detect at least a position (a distanceand orientation) of the object. The radar device 12 is attached to anylocation on the host vehicle M. The radar device 12 may detect aposition and a speed of the object using a frequency modulatedcontinuous wave (FM-CW) scheme.

The LIDAR 14 irradiates the surroundings of the host vehicle M withlight (or an electromagnetic wave having a wavelength close to that oflight) and measures scattered light. The LIDAR 14 detects a distance toa target on the basis of a time from light emission to light reception.The light to be radiated is, for example, pulsed laser light. The LIDAR14 is attached to any location on the host vehicle M.

The object recognition device 16 performs sensor fusion processing ondetection results of some or all of the camera 10, the radar device 12,and the LIDAR 14 to recognize a position, type, speed, and the like ofthe object. The object recognition device 16 outputs recognition resultsto the automated driving control device 100. The object recognitiondevice 16 may output detection results of the camera 10, the radardevice 12, and the LIDAR 14 as they are to the automated driving controldevice 100. In this case, the object recognition device 16 may beomitted from the vehicle system 1.

The communication device 20, for example, communicates with anothervehicle present around the host vehicle M using a cellular network, aWi-Fi network, Bluetooth (registered trademark), dedicated short rangecommunication (DSRC), or the like or communicates with various serverdevices via a wireless base station.

The HMI 30 presents various types of information to a user of the hostvehicle M and receives an input operation from the user. Examples of theuser include a driver who drives the host vehicle M and an occupant suchas a fellow passenger. In the following description, the term “occupant”will be used unless otherwise specified. The HMI 30 includes, forexample, a display 32, a speaker 34, and a blinker switch 36. The HMI 30may include buzzers, a touch panel, switches, keys, microphones, and thelike.

The display 32 is, for example, located under the front windshield andprovided in a dashboard provided in front of a seat of the driver and aseat of a front occupant in a vehicle cabin. The display 32 may beprovided near the front of the seat of the driver (a seat closest to asteering wheel), for example, and installed at a position visible to thedriver through a gap in the steering wheel or through the steeringwheel.

The display 32 is, for example, any of various display devices such as aliquid crystal display (LCD) and an organic electro luminescence (EL)display. The display 32 displays an image output by an HMI controller170, which will be described later. The display 32 may be a touch panelthat receives an operation of the occupant on a screen. The display 32may function as an instrument panel (meter display) that displaysinstruments such as a speedometer and a tachometer.

At least one speaker 34 is installed in the vehicle cabin. The speaker34 outputs a voice, a warning sound, or the like under the control ofthe HMI controller 170, for example.

The blinker switch 36 is provided, for example, on a steering column ora steering wheel. The blinker switch 36 is an example of an operatorthat receives an instruction from the driver to perform lane change ofthe host vehicle M, for example. The blinker switch 36, for example, maybe a blinker lever or may be a blinker button. For example, when thedriver operates the blinker switch 36 in a direction in which the lanechange (course change) of the host vehicle M is performed (a directionin which the host vehicle M moves), a direction indicator (for example,a blinker (a blinker outside the vehicle)) indicating the direction inwhich the host vehicle M moves, to the surroundings, blinks.

The vehicle sensor 40 includes, for example, a vehicle speed sensor thatdetects a speed of the host vehicle M, an acceleration sensor thatdetects an acceleration, a yaw rate sensor that detects an angular speedaround a vertical axis, and an orientation sensor that detects adirection of the host vehicle M. The vehicle sensor 40 may include aposition sensor that acquires a position of the host vehicle M. Theposition sensor is, for example, a sensor that acquires positioninformation (longitude and latitude information) from a globalpositioning system (GPS) device. The position sensor may be a sensorthat acquires the position information using a global navigationsatellite system (GNSS) receiver 51 of the navigation device 50.

The navigation device 50 includes, for example, the GNSS receiver 51, anavigation HMI 52, and a route determiner 53. The navigation device 50holds first map information 54 in a storage device such as a hard diskdrive (HDD) or a flash memory. The GNSS receiver 51 specifies theposition of the host vehicle M on the basis of a signal received from aGNSS satellite. The position of the host vehicle M may be specified orcomplemented by an inertial navigation system (INS) using an output ofthe vehicle sensor 40. The navigation HMI 52 includes a display device,a speaker, a touch panel, keys, and the like. The navigation HMI 52 maybe partly or wholly shared with the HMI 30 described above. The routedeterminer 53, for example, determines a route (hereinafter, an on-maproute) from the position of the host vehicle M specified by the GNSSreceiver 51 (or any input position) to a destination input by theoccupant using the navigation HMI 52 by referring to the first mapinformation 54. The first map information 54 is, for example,information in which a road shape is represented by links indicatingroads and nodes connected by the links. The first map information 54 mayinclude a curvature of the road, point of interest (POI) information,and the like. The on-map route is output to the MPU 60. The navigationdevice 50 may perform route guidance using the navigation HMI 52 on thebasis of the on-map route. The navigation device 50 may be realized, forexample, by a function of a terminal device such as a smartphone or atablet terminal possessed by the occupant. The navigation device 50 maytransmit a current position and a destination to a navigation server viathe communication device 20 and acquire the same route as the on-maproute from the navigation server.

The MPU 60 includes, for example, a recommended lane determiner 61, andholds second map information 62 in a storage device such as an HDD or aflash memory. The recommended lane determiner 61 divides the on-maproute provided from the navigation device 50 into a plurality of blocks(for example, divides the route every 100 [m] in a traveling directionof the vehicle), and determines a recommended lane for each block byreferring to the second map information 62. The recommended lanedeterminer 61 determines in which lane from the left the host vehicle Mtravels. The recommended lane determiner 61 determines the recommendedlane so that the host vehicle M can travel on a reasonable route fortravel to a branch destination when there is a branch location in theon-map route.

The second map information 62 is map information with higher accuracythan the first map information 54. The second map information 62includes, for example, information on a center of the lane orinformation on a boundary of the lane. The second map information 62 mayinclude information on the number of lanes or a width (lane width) of aroad. The second map information 62 may include information indicating abranch section in which a main lane and a branch lane are connected, andinformation indicating a merging section in which the main lane and amerging lane that merges into the main lane are connected. Theinformation indicating the branch section includes, for example,position information of a start point and an end point of the branchsection, the number of branch lanes, and lane connection informationindicating how the lanes are connected. The information indicating themerging section includes, for example, position information of a startpoint and an end point of the merging section. The second mapinformation 62 includes, for example, information on a position of aconnection edge (nose) of a lane in the branch section or the mergingsection or a position of a zebra zone (traffic zone) or a no-entry area,information indicating whether or not there is a road demarcation line(hereinafter referred to as a demarcation line) that demarcates the mainlane and another lane (a branch lane or a merging lane), and shapeinformation of the branch section or the merging section. The connectionend includes, for example, a soft nose and a hard nose. The second mapinformation 62 may include road information, traffic regulationinformation, address information (an address and postal code), facilityinformation, telephone number information, and the like. The second mapinformation 62 may be updated at any time by the communication device 20communicating with another device.

The driving operator 80 includes, for example, an accelerator pedal, abrake pedal, a shift lever, a steering wheel, a deformed steering wheel,a joystick, and other operators. A sensor that detects an amount ofoperation or the presence or absence of the operation is attached to thedriving operator 80, and a result of the detection is output to theautomated driving control device 100 or some or all of the traveldriving force output device 200, the brake device 210, and the steeringdevice 220.

The automated driving control device 100 includes, for example, a firstcontroller 120, a second controller 160, the HMI controller 170, and astorage 180. The first controller 120, the second controller 160, andthe HMI controller 170 are realized, for example, by a hardwareprocessor such as a central processing unit (CPU) executing a program(software). Some or all of these components may be realized by hardware(circuit; including circuitry) such as a large scale integration (LSI),an application specific integrated circuit (ASIC), a field-programmablegate array (FPGA), or a graphics processing unit (GPU), or may berealized by software and hardware in cooperation. The program may bestored in a storage device (a storage device including a non-transitorystorage medium) such as an HDD or a flash memory of the automateddriving control device 100 in advance or may be stored in a detachablestorage medium such as a DVD or a CD-ROM and installed in the HDD orflash memory of the automated driving control device 100 by the storagemedium (a non-transitory storage medium) being mounted in a drivedevice. The automated driving control device 100 is an example of a“vehicle control device”.

The storage 180 may be realized by various storage devices describedabove, a solid state drive (SSD), an electrically erasable programmableread only memory (EEPROM), a read only memory (ROM), a random accessmemory (RAM), or the like. Information necessary for execution of thedriving control in the first embodiment, programs, and various types ofother information, for example, are stored in the storage 180. Thestorage 180 may store map information (the first map information 54 andthe second map information 62).

FIG. 2 is a functional configuration diagram of the first controller 120and the second controller 160. The first controller 120 realizes, forexample, a function using artificial intelligence (AI) and a functionusing a previously given model in parallel. For example, a function of“recognizing an intersection” may be realized by recognition of theintersection using deep learning or the like and recognition based onpreviously given conditions (there is a signal which can be subjected topattern matching, a road sign, or the like) being executed in paralleland scored for comprehensive evaluation. Accordingly, the reliability ofautomated driving is ensured. The first controller 120 includes, forexample, a recognizer 130, a determiner 140, and an action plangenerator 150. A combination of the determiner 140, the action plangenerator 150, and the second controller 160 is an example of the“driving controller”.

The recognizer 130 recognizes the surroundings situation of the hostvehicle M on the basis of information obtained from at least one of thedetection device DD and the map information. For example, the recognizer130 recognizes a state such as a position, speed, and acceleration of anobject around the host vehicle M (for example, within a predetermineddistance from the host vehicle M) on the basis of the informationacquired from the detection device DD. Examples of the object includeother vehicles, traffic participants on a road (pedestrians, bicycles,or the like), road structures, and other surrounding objects. Examplesof the road structure include a road sign, a traffic light, a railroadcrossing, a curb, a median, a guardrail, and a fence. Examples of theroad structure may include a road surface sign such as a demarcationline drawn or affixed on a road surface that demarcates the road, apedestrian crossing, a bicycle crossing, a stop line, a zebra zone(traffic zone), or a no-entry area, and a connection edge (a soft noseor hard nose) of the lane. The position of the object, for example, isrecognized as a position at absolute coordinates with a representativepoint (a centroid, a drive shaft center, or the like) of the hostvehicle M as an origin, and is used for control. The position of theobject may be indicated by a representative point such as a centroid ora corner of the object or may be indicated by a represented area. In thefollowing description, it is assumed that the representative point ofthe host vehicle M is the centroid. When the object is another vehicle,the “status” of the object may include an acceleration or jerk of theobject, or an “action status” (for example, whether or not the object ischanging lanes or is about to change lanes). The recognizer 130 mayrecognize a relative distance (a residual distance) to the object.

The recognizer 130, for example, recognizes the number of lanes of aroad on which the host vehicle M is traveling or the traveling lane(host vehicle lane) on the basis of the information acquired from thedetection device DD. In this case, the recognizer 130 may compare apattern (for example, a line type or layout of solid lines and dashedlines) of a demarcation line obtained from the second map information 62with a pattern of a demarcation line around the host vehicle Mrecognized from an image captured by the camera 10 to recognize thetraveling lane. The recognizer 130 may recognize a lane boundary (roadboundary) of a road structure as well as the demarcation lines torecognize the traveling lane. In this recognition, the position of thehost vehicle M acquired from the navigation device 50 or a processingresult of the INS may be taken into consideration.

The recognizer 130 recognizes a position or posture of the host vehicleM with respect to the traveling lane when recognizing the travelinglane. The recognizer 130 may recognize, for example, a deviation of areference point of the host vehicle M from a center of the lane and anangle formed between a traveling direction of the host vehicle M and aline connecting along the center of the lane as a relative position andposture of the host vehicle M with respect to the traveling lane.Instead, the recognizer 130 may recognize, for example, a position ofthe reference point of the host vehicle M with respect to any one sideedge (the demarcation line or the road boundary) of the traveling laneas the relative position of the host vehicle M with respect to thetraveling lane. The recognizer 130 recognizes a stop line, an obstacle,a traffic light, a toll booth, and other road events.

The recognizer 130 recognizes a branch section present in front of thehost vehicle M, the lane connection information in the branch section,and various types of information for travel in the branch section, suchas lane type. A function of the recognizer 130 in this case will bedescribed in detail later.

The determiner 140 performs various determination processing such as adetermination as to whether or not the occupant of the host vehicle M isnotified of predetermined information, a determination as to whether ablinker (a direction indicator) mounted on the host vehicle M is to beoperated, and a determination as to whether lateral movement for coursechange (lane change) from the main lane side to the branch lane side isto be started, on the basis of the recognition result of the recognizer130. A function of the determiner 140 will be described in detail later.

The action plan generator 150 generates a target trajectory along whichthe host vehicle M will travel in the future automatically (withoutdepending on an operation of a driver) so that the host vehicle M canbasically travel in the recommended lane determined by the recommendedlane determiner 61 and cope with a surroundings situation of the hostvehicle M, on the basis of the recognition result of the recognizer 130or the determination result of the determiner 140. The target trajectoryincludes, for example, a speed element. For example, the targettrajectory is represented as a sequence of points (trajectory points) tobe reached by the host vehicle M. The trajectory point is a point thatthe host vehicle M is to reach for each predetermined traveling distance(for example, several meters) along a road, and a target speed and atarget acceleration at every predetermined sampling time (for example,every several tenths of a [sec]) are separately generated as a part ofthe target trajectory. The trajectory point may be a position to bereached by the host vehicle M at the sampling time at everypredetermined sampling time. In this case, information on the targetspeed or the target acceleration is represented by an interval betweenthe trajectory points.

When the action plan generator 150 generates the target trajectory, theaction plan generator 150 may set an event of automated driving.Examples of the automated driving event include a constant speedtraveling event, a low speed following traveling event, a lane changingevent, a branching event, a merging event, a takeover event, and anemergency stop event. The action plan generator 150 generates a targettrajectory according to an activated event. The action plan generator150 performs, for example, adjustment of the speed of the host vehicle Mor adjustment of an amount of lateral movement of the host vehicle Mwhen generating the target trajectory. A function of the action plangenerator 150 will be described in detail later.

The second controller 160 controls the travel driving force outputdevice 200, the brake device 210, and the steering device 220 so thatthe host vehicle M passes through the target trajectory generated by theaction plan generator 150 at a scheduled time.

The second controller 160 includes, for example, an acquirer 162, aspeed controller 164, and a steering controller 166. The acquirer 162acquires information on the target trajectory (trajectory points)generated by the action plan generator 150 and stores the information onthe target trajectory in a memory (not shown). The speed controller 164controls the travel driving force output device 200 or the brake device210 on the basis of a speed element incidental to the target trajectorystored in the memory. The steering controller 166 controls the steeringdevice 220 according to a bent state of the target trajectory stored inthe memory. Processing of the speed controller 164 and the steeringcontroller 166 is realized by, for example, a combination of feedforwardcontrol and feedback control. For example, the steering controller 166executes a combination of feedforward control according to a curvatureof a road in front of the host vehicle M with feedback control based ona deviation from the target trajectory.

The HMI controller 170 uses the HMI 30 to notify the occupant ofpredetermined information. Examples of the predetermined informationinclude information related to traveling of the host vehicle M, such asinformation on a state of the host vehicle M or information on drivingcontrol. Examples of the information on the state of the host vehicle Minclude a speed of the host vehicle M, an engine speed, and a shiftposition. Examples of the information on the driving control include aninquiry as to whether or not to change lanes, information imposed on theoccupant required for switching from automated driving to manual drivingor the like (task request information for the occupant), and informationon a situation of driving control (for example, content of an event thatis being executed). The predetermined information may includeinformation irrelevant to travel control of the host vehicle M, such asTV programs, and content (for example, movies) stored in a storagemedium such as a DVD.

For example, the HMI controller 170 may generate an image including theabove-described predetermined information and cause the generated imageto be displayed on the display 32 of the HMI 30 or may generate a soundindicating the predetermined information and cause the generated soundto be output from the speaker 34 of the HMI 30. The HMI controller 170may output the information received by the HMI 30 to the communicationdevice 20, the navigation device 50, the first controller 120, and thelike.

The travel driving force output device 200 outputs a travel drivingforce (torque) for traveling of the vehicle to driving wheels. Thetravel driving force output device 200 includes, for example, acombination of an internal combustion engine, an electric motor, atransmission, and the like, and an electronic control unit (ECU) thatcontrols these. The ECU controls the above configuration according toinformation input from the second controller 160 or information inputfrom the driving operator 80.

The brake device 210 includes, for example, a brake caliper, a cylinderthat transfers hydraulic pressure to the brake caliper, an electricmotor that generates hydraulic pressure in the cylinder, and a brakeECU. The brake ECU controls the electric motor according to theinformation input from the second controller 160 or the informationinput from the driving operator 80 so that a brake torque according to abraking operation is output to each wheel. The brake device 210 mayinclude a mechanism that transfers the hydraulic pressure generated byan operation of the brake pedal included in the driving operator 80 tothe cylinder via a master cylinder, as a backup. The brake device 210 isnot limited to the configuration described above and may be anelectronically controlled hydraulic brake device that controls anactuator according to the information input from the second controller160 and transfers the hydraulic pressure of the master cylinder to thecylinder.

The steering device 220 includes, for example, a steering ECU and anelectric motor. The electric motor, for example, changes directions ofsteerable wheels by causing a force to act on a rack and pinionmechanism. The steering ECU drives the electric motor according to theinformation input from the second controller 160 or the informationinput from the driving operator 80 to change the directions of thesteerable wheels.

[Functions of Recognizer, Determiner, and Action Plan Generator]

Next, functions of the recognizer 130, the determiner 140, and theaction plan generator 150 will be described in detail. FIG. 3 is adiagram showing an example of functional configurations of therecognizer 130, the determiner 140, and the action plan generator 150.The recognizer 130 includes, for example, a virtual demarcation linesetter 132, a branch lane shape estimator 134, and a branch residualdistance deriver 136.

The virtual demarcation line setter 132 determines whether or not thereis a branch section within a predetermined distance in the travelingdirection of the host vehicle M on the basis of the surroundingssituation of the host vehicle M acquired from the map information on thebasis of a recognition result of the surroundings situation of the hostvehicle M according to the above-described sensor fusion processing andthe position of the host vehicle M. When the virtual demarcation linesetter 132 determines that there is the branch section within thepredetermined distance in the traveling direction of the host vehicle M,the virtual demarcation line setter 132 further determines whether ornot a demarcation line that demarcates the main lane side and the branchlane side in the branch section can be recognized on the basis of therecognition result, and sets a virtual demarcation line that demarcatesthe main lane and the branch lane when a demarcation line cannot berecognized.

FIG. 4 is a diagram for describing a function of the virtual demarcationline setter 132. The example of FIG. 4 shows a road RD1 including mainlanes L1 (L1 a and L1 b) and L2 (L2 a and L2 b) and a branch lane L3.Both the lanes L1 and L2 are lanes in which a vehicle can travel in thesame direction (a direction in which the lane extends or an X-axisdirection in FIG. 4 ). The lane L1 is demarcated by a left demarcationline LL and a right demarcation line LR with respect to the travelingdirection. In the example of FIG. 4 , the host vehicle M is traveling onthe lane L1 at a speed VM. Information on the demarcation lines LL andLR and the lanes L1 and L2 may be acquired by sensor fusion processing,or may be acquired by map information (the first map information 54 andthe second map information 62).

The virtual demarcation line setter 132 refers to the map information toacquire a shape of the road RD1, the number of lanes, and positioninformation of a start position (hereinafter referred to as a branchsection start point) SP1 of a branch section RS1 in which the main lane(the lanes L1 and L2) and the branch lane L3 are connected, and an endposition (hereinafter referred to as a branch section end point) EP1 ofthe branch section RS1, on the basis of position information of the hostvehicle M detected by the vehicle sensor 40. The branch section startpoint SP1 is, for example, a point that is on the front side of the roadwhen viewed in the traveling direction among connection points at whichthe branch lane L3 and the main lane (specifically, L1) are connected.The branch section end point EP1 is, for example, a point on the innerside of the road when viewed in the traveling direction among theconnection points, and is a point corresponding to a start position ofthe branch lane L3.

The virtual demarcation line setter 132 determines whether thedemarcation line (a branch side demarcation line) that demarcates themain lane side and the branch lane side can be recognized on the branchlane side (branch side) when viewed from the lane L1 in which the hostvehicle M travels, in the branch section RS1 from the branch sectionstart point SP1 to the branch section end point EP1 in a direction inwhich the main lane (the lanes L1 and L2) extends, on the basis of therecognition result of the recognizer 130. When a determination is madethat the branch side demarcation line can be recognized, a targettrajectory is generated so that the host vehicle M passes through acenter CL1 of the lane L1 on the basis of the demarcation line (mainlane side demarcation line) LR that demarcates the lanes L1 and L2 onthe main lane side (lane L2), and the branch side demarcation line, anddriving control is executed so that the host vehicle M travels along thegenerated target trajectory.

When the virtual demarcation line setter 132 determines that the branchside demarcation line cannot be recognized in the branch section RS1,the virtual demarcation line setter 132 sets a virtual demarcation linebetween the branch section start point SP1 and the branch section endpoint EP1. In this case, the virtual demarcation line setter 132determines, for example, an offset amount (a distance from a main laneside demarcation line) OST based on the position of the main lane sidedemarcation line (specifically, the demarcation line LR) in the mapinformation, and sets a virtual demarcation line on the basis of thedetermined offset amount OST.

For example, the virtual demarcation line setter 132 refers to the mapinformation or the like to acquire a distance W1 to the demarcation lineLR in a road width direction (a Y-axis direction in the figure) withreference to the branch section start point SP1 and a distance W2 to thedemarcation line LR in the road width direction with reference to thebranch section end point EP1. That is, the distance W1 is a width of thelane L1 at the branch section start point SP1, and the distance W2 is awidth of the lane L1 at the branch section end point EP1. When thevirtual demarcation line setter 132 sets a virtual demarcation line VL1connecting the branch section start point SP1 to the branch section endpoint EP1, the virtual demarcation line setter 132 sets the virtualdemarcation line VL1 so that a distance in the road width directionbetween the demarcation line LR and the virtual demarcation line VL1(the offset amount OST from the demarcation line LR) changes (increasesor decreases) by a predetermined change amount from the distance W1 tothe distance W2.

This makes it possible to set a smooth virtual demarcation line whilekeeping an amount of change in a width of the traveling lane constant(monotonically increasing or monotonously decreasing the amount) even inthe case of a road shape in which a width (that is, the distance W1) ofthe traveling lane L1 a before branching and a width (that is, thedistance W2) of the traveling lane L1 b after branch are different, forexample, as shown in FIG. 4 . Therefore, it is possible to generate atarget trajectory in which a centroid of the host vehicle M passesthrough a center between the virtual demarcation line VL1 and thedemarcation line LR, for example, when generating a target trajectorytraveling toward the lane L1 b in the branch section RS1, and thus, itis possible for the host vehicle M to travel smoothly without laterallymoving to the branch lane side even when there is the branch sectionRS1. When the host vehicle M performs lane change (course change) fromthe lane L1 to the branch lane L3, travel control is executed withreference to the virtual demarcation line VL1, and thus, moreappropriate lane change control (speed control and steering control) isexecuted.

The virtual demarcation line setter 132 may set a virtual demarcationline for each branch section end point when there are a plurality ofbranch section end points EP depending on a shape of a road. FIG. 5 is adiagram showing an example in which virtual demarcation lines are setwhen there are a plurality of branch section end points. A road RD1#shown in FIG. 5 differs from the road RD1 in FIG. 4 in that there aretwo branch section end points EP1 and EP2. As shown in FIG. 5 , examplesin which there are a plurality of branch section end points EP includesa case in which there is a road structure OB1 such as a separation zone,a guardrail, or a fence between a main lane (more specifically, the laneL1 b) and the branch lane L3 and a case in which a width (a length inthe Y-axis direction in the figure) of the hard nose or the soft nose isequal to or greater than a predetermined value when viewed from thetraveling direction. In the example of FIG. 5 , the two branch sectionend points EP1 and EP2 are present in the hard nose, and positioninformation of the two branch section end points EP1 and EP2 is storedin the map information.

The virtual demarcation line setter 132 acquires the positioninformation of the branch section start point SP1 and the branch sectionend points EP1 and EP2 from the map information, and also acquires theposition information of the demarcation line LR on the main lane (thelane L2 in FIG. 5 ) side of the traveling lane L1 of the host vehicle M.The virtual demarcation line setter 132 sets a virtual demarcation linewhen one or both of a demarcation line connecting the branch sectionstart point SP1 to the branch section end point EP1 and a demarcationline connecting the branch section start point SP1 to the branch sectionend point EP2 are not present.

For example, when there is no demarcation line connecting the branchsection start point SP1 to the branch section end point EP1, the virtualdemarcation line setter 132 acquires the distance W1 in the road widthdirection from the branch section start point SP1 to the demarcationline LR and the distance W2 in the road width direction from the branchsection end point EP1 to the demarcation line LR as described above, andsets the virtual demarcation line VL1 connecting the branch sectionstart point SP1 to the branch section end point EP1 when setting thevirtual demarcation line VL1 so that the distance in the road widthdirection between the demarcation line LR and the virtual demarcationline VL1 (the offset amount OST from the demarcation line LR) changes bythe predetermined change amount from the distance W1 to the distance W2.Further, similarly, when there is no demarcation line connecting thebranch section start point SP1 to the branch section end point EP2, thevirtual demarcation line setter 132 acquires the distance W1 and adistance W3 in the road width direction from the branch section endpoint EP2 to the demarcation line LR, and sets a virtual demarcationline VL2 connecting the branch section start point SP1 to the branchsection end point EP2 so that a distance in the road width directionbetween the demarcation line LR and the virtual demarcation line VL2(the offset amount OST from the demarcation line LR) changes by apredetermined change amount from the distance W1 to the distance W3 whensetting the virtual demarcation line VL2. In the example of FIG. 5 , thelinear virtual demarcation lines VL1 and VL2 are set according to apredetermined amount of change. Even when there are three or more branchsection end points, the virtual demarcation line setter 132 sets avirtual demarcation line for each branch section end point using theabove-described scheme.

Accordingly, for example, when the host vehicle M continues to travel inthe lane L1 in the branch section RS1, the target trajectory is set sothat the host vehicle M travels at a center between the virtualdemarcation line VL1 and the main lane side demarcation line LR. Whenthe host vehicle M changes lanes from the lane L1 to the branch lane L3,the travel control of the host vehicle M is executed with reference tothe virtual demarcation line VL1 until the lane change to the lane L3 isstarted, switching to the virtual demarcation line VL2 is performed atthe time of the start of the steering control due to the lane change,and control of the lane change (speed control and steering control) ofthe host vehicle M is executed.

The action plan generator 150 (a lateral movement adjuster 154 whichwill be described later) may switch the virtual demarcation line servingas a reference for steering control at the time of course change toadjust the target trajectory so that an amount of movement (for example,an amount of lateral movement) of the host vehicle M between before andafter switching between the virtual demarcation lines VL1 and VL2 issmaller than a predetermined amount to prevent a trajectory of the hostvehicle M from greatly changing (to make an amount of change in steeringsmaller than a threshold). This makes it possible to cause the hostvehicle M to smoothly travel and to reduce discomfort felt by occupantsduring travel even when switching between the virtual demarcation linesserving as travel control targets has been performed.

The virtual demarcation line setter 132 sets both the virtualdemarcation lines VL1 and VL2 in advance, even when the host vehicle Mcontinues to travel in the lane L1 and changes lanes from the lane L1 tothe lane L3. This makes it possible to suppress a loss of time due tothe setting of the demarcation line at a point in time when the hostvehicle M suddenly performs the course change to the branch lane L3according to an operation (for example, a blinker operation) of theoccupant of the host vehicle M during traveling in the branch sectionRS1, for example, in a case in which the host vehicle M suddenlyperforms course change, and to suppress a large behavior of the hostvehicle M due to a loss of time.

As described above, when there are a plurality of branch section endpoints, the virtual demarcation line setter 132 sets a virtualdemarcation line corresponding to each branch section end point, makingit possible to set a more accurate virtual demarcation line according toroad conditions as compared to a case in which a single virtualdemarcation line is set on the basis of a way point of the plurality ofbranch section end points. Therefore, when the vehicle travels on thebasis of the virtual demarcation line, it is possible to execute drivingcontrol in which discomfort given to occupants of the host vehicle M isreduced.

When the virtual demarcation line is set by the virtual demarcation linesetter 132, the HMI controller 170 may cause information on the virtualdemarcation line to be output to the display 32 of the HMI 30, or thelike. This makes it possible for the occupant to easily ascertain thatcontrol of lane change or the like is being executed on the basis of thevirtual demarcation line in automated driving or the like, and tofurther reduce anxiety based on change in a behavior of the host vehicleM.

Referring back to FIG. 3 , the branch lane shape estimator 134 acquiresthe virtual demarcation line set by the virtual demarcation line setter132, the road shape (a shape of the branch section and the branch lane)acquired from the map information, the number of branch lanes, a type ofbranch, and a type of demarcation line. Examples of the type of branchinclude “single-opening branching”, “double-opening branching”,“three-branch branching”, “outward branching (branching to an outer sideof a curve)”, and “inward branching (branching to an inner side of acurve)”. The branch lane shape estimator 134 estimates a position of acenter of each lane of the branch lane.

The branch lane shape estimator 134 includes, for example, anumber-of-lanes increase position searcher 134 a. The number-of-lanesincrease position searcher 134 a, for example, acquires a position ofthe branch section from map information or the like, and searches for aposition at which the number-of-lanes increase starts on the branch side(number-of-lanes increase start position) in the acquired branchsection. A function of the branch lane shape estimator 134 will bedescribed in detail later.

The branch residual distance deriver 136 derives one or both of aresidual distance from a current position (a host vehicle position) ofthe host vehicle M to the branch section start point and a residualdistance to the branch end position according to a detection result ofthe vehicle sensor 40. The branch residual distance deriver 136 mayderive a residual distance from the host vehicle position to thenumber-of-lanes increase start position.

The determiner 140 determines whether or not course change (lane change)in the branch section is to be started on the basis of the recognitionresult of the recognizer 130 (for example, the branch residual distancederived by the branch residual distance deriver 136, the number oflanes, the lane connection information, and a host vehicle laneposition). The determiner 140 includes, for example, a recommendationstart determiner 142 and a blinker lighting start determiner 144.

For example, when at least part of the driving control of the hostvehicle M is executed by manual driving, the recommendation startdeterminer 142 determines whether or not recommendation for promptingthe occupant of the host vehicle M to perform lane change or the like isto be started, on the basis of the position of the host vehicle M, themap information, the destination, and the recognition result of therecognizer 130. For example, the recommendation start determiner 142determines that recommendation for prompting the occupant to performlane change is to be started when a distance from the position of thehost vehicle M to the branch section start point or the number-of-lanesincrease start position is within a predetermined distance and adestination direction (traveling direction) of the host vehicle M is alane (for example, a branch side lane) different from a currenttraveling lane (for example, the main lane). The recommendation startdeterminer 142 determines that the recommendation is not started whenthe destination direction is the traveling lane (when there is no needto perform lane change) even when a distance of the host vehicle M fromthe branch section is smaller than a predetermined distance.

When the recommendation start determiner 142 determines that the lanechange recommendation is to be started, the recommendation startdeterminer 142 outputs, to the HMI controller 170, control informationfor causing a notification for prompting the occupant of the hostvehicle M to perform lane change to be output to the HMI 30. The HMIcontroller 170, for example, generates an image for prompting lanechange in the branch section, and outputs the generated image to thedisplay 32 of the HMI 30. The HMI 30 may generate sound instead of (orin addition to) the image, and cause the generated sound to be outputfrom the speaker 34.

The blinker lighting start determiner 144 determines whether or notlighting of blinkers mounted on the host vehicle M has been started. Forexample, when the blinker lighting start determiner 144 receives anoperation with respect to the blinker switch 36 by the occupant, theblinker lighting start determiner 144 determines that blinkering of theblinker in a direction (a right direction or left direction) of the lanechange operated by the blinker switch 36 has been started. When theblinker lighting start determiner 144 determines that lighting of theblinker has been started after the recommendation start determiner 142has determined that the recommendation is to be started, the blinkerlighting start determiner 144 outputs information indicating that anintention of the occupant for execution of driving control (for example,ALC) according to the recommendation has been received, to the actionplan generator 150.

The action plan generator 150 generates a target trajectory for futuretravel with reference to the current position of the host vehicle M onthe basis of the recognition result of the recognizer 130 (for example,the branch residual distance derived by the branch residual distancederiver 136, the number of lanes, the lane connection information, thehost vehicle lane, and a demarcation line shape) or the like. The actionplan generator 150 includes, for example, a speed adjuster 152, alateral movement adjuster 154, and a route generator 156.

The speed adjuster 152 adjusts the speed of the host vehicle M when thehost vehicle M performs course change to the branch lane, on the basisof the branch residual distance derived by the branch residual distancederiver 136, the position (traveling lane) of the host vehicle M, thenumber of lanes, or the lane connection information, for example. Thespeed adjuster 152 may adjust a speed when the host vehicle M continuesto travel in the main lane in the branch section, and may perform speedadjustment not in the branch section or others according to thesurroundings situation (the road shape or surrounding vehicles).

The lateral movement adjuster 154 adjusts a lateral position (a positionin the road width direction) of the host vehicle M with respect to theroad on the basis of the virtual demarcation line set by the virtualdemarcation line setter 132, demarcation line information (shape ortype) acquired from the map information, demarcation line informationobtained from a result of recognizing the image captured by the camera10, and the like. The lateral movement adjuster 154 may perform, forexample, adjustment such as steering control required by the hostvehicle M at a target lateral position at a certain point, on the basisof speed information of the host vehicle M adjusted by the speedadjuster 152. The lateral movement adjuster 154 may adjust, for example,a position at which the steering control starts or a position at whichthe steering control ends, an amount of movement of the lateral positionin a predetermined period of time, and the like. When the recognizer 130recognizes that an object (for example, another vehicle) is presentaround the host vehicle M, the speed adjuster 152 and the lateralmovement adjuster 154 described above perform adjustment of speedcontrol or lateral movement control so that the host vehicle M does notcome into contact with the recognized object.

The route generator 156, for example, generates a target trajectory(travel route) for lane change from the main lane to the branch lane inthe branch section on the basis of the current position of the hostvehicle M, an adjustment result of the speed adjuster 152 or the lateralmovement adjuster 154, and the like, or generates a target trajectoryfor continuous travel in the main lane. The route generator 156, forexample, repeatedly generates the target trajectory at a predeterminedcycle. A route generated by the route generator 156 is output to thesecond controller 160, and speed control or steering control is executedso that the host vehicle M travels along the generated targettrajectory.

[Branch Lane Shape Estimator and Lane Change in Branch Section]

Next, the function of the branch lane shape estimator 134 in the firstembodiment and the lane change in the branch section based on anestimation result will be specifically described. FIG. 6 is a diagramfor describing generation of the target trajectory when the lane changeis performed in the branch section. The example of FIG. 6 shows a roadRD2 having two lanes (L1 and L2) that can travel in the same direction,and two branch lanes L3 and L4. In the example of FIG. 6 , it is assumedthat the centroid of the host vehicle M is on the center CL1 of the laneL1, and the host vehicle M is traveling at a point that is at a distanceD1 before the branch section (the branch section start point SP1) at thespeed VM. In the example of FIG. 6 , it is assumed that the destinationdirection of the host vehicle M is on the side of the branch lanes L3and L4. Further, in FIG. 6 , a length of half the width of the lane L1(in other words, a lateral distance from the demarcation line LL or LRto the center CL1) is W11, half the width of the branch lane L4 (alateral distance from a demarcation line of the lane L4 to a center CL4of the lane L4) is W12, a length of half the width of the branch lane L3(a lateral distance from a demarcation line of the lane L3 to a centerCL3 of the lane L3) is W14, and a length that is a sum of the lengthsW12 and W14 is W13. In the example of FIG. 6 , the distance D1 is theresidual distance from the current position of the host vehicle M to thebranch section start point SP1 derived by the branch residual distancederiver 136.

In a scene of FIG. 6 , the virtual demarcation line setter 132determines whether or not the demarcation line that demarcates the mainlane side (the lane L1) and the branch lane side is recognized, on thebasis of the recognition result of the recognizer 130 or the mapinformation, in the branch section RS1 from the branch section startpoint SP1 to the branch section end point EP1, and sets the virtualdemarcation line VL1 connecting the branch section start point SP1 tothe branch section end point EP1 as described above when the demarcationline is not recognized. When the demarcation line that demarcates themain lane side and the branch lane side is recognized, subsequentprocessing is performed using the recognized demarcation line withoutsetting the virtual demarcation line. In the following description, itis assumed that the virtual demarcation lines are set by the virtualdemarcation line setter 132.

Here, in the branch section RS1, when there are no demarcation lines ofthe lanes L3 and L4, a lane width between the demarcation line LR and ademarcation line SL1 gradually increases, and thus, the host vehicle Mtries to travel at a center thereof and performs unnecessary steeringcontrol or the host vehicle M travels while interfering with the virtualdemarcation line VL1 (in other words, travels on the virtual demarcationline VL1), which may not be appropriate driving control, for example, togive discomfort to the occupants. Therefore, when the host vehicle Mchanges lanes from the lane L1 to the lane L3 or L4, the action plangenerator 150 generates a target trajectory so that a degree ofinterference with the virtual demarcation line VL1 is reduced, on thebasis of, for example, the branch lane shape estimated by the branchlane shape estimator 134. Reducing the degree of interference betweenthe virtual demarcation line VL1 and the target trajectory means, forexample, preventing the host vehicle M traveling along the targettrajectory from traveling on the virtual demarcation line VL1, in otherwords, setting a distance between the virtual demarcation line VL1 andthe target trajectory to a predetermined distance or more. “Reducing thedegree of interference with the virtual demarcation line VL1” may berephrased as “suppressing the interference with the virtual demarcationline VL1.”

The branch lane shape estimator 134 estimates a shape of a demarcationline on the outermost side (an outermost demarcation line) SL1 of thebranch lanes L3 and L4 on the basis of the recognition result of therecognizer 130 or the map information. The branch lane shape estimator134 may estimate a shifted demarcation line (outermost demarcation line)SL1 so that an amount of offset from the virtual demarcation line VL1becomes a predetermined amount of change (for example, increases to apredetermined amount) with respect to a movement in the X-axis directionfrom the branch section start point SP1 to a branch edge position BP1 (amovement by the distance D11 in the figure) on the basis of the virtualdemarcation line VL1 set by the virtual demarcation line setter 132.

The branch lane shape estimator 134 determines an edge position (branchedge position) of each of the branch lanes L3 and L4. The branch edgeposition is, for example, a position at which widths of all branch lanescan be determined. For example, in FIG. 6 , an edge BP1 of a demarcationline BL1 that demarcates the lane L3 and the lane L4 is present at aposition before the branch section end point EP1 when viewed from thehost vehicle M, and the widths of the lanes L3 and L4 can be recognizedfrom the edge BP1, the demarcation line on the outermost side (outermostdemarcation line) SL1 of the branch lane, and the virtual demarcationline VL1. Therefore, the branch lane shape estimator 134 determines aposition of the edge BP1 as the branch edge position.

The number-of-lanes increase position searcher 134 a of the branch laneshape estimator 134 searches for a number-of-lanes increase startposition ISP1 in the branch section RS1. In this case, thenumber-of-lanes increase start position ISP1 is searched for on thebasis of a predetermined parameter k and a shape of the outermostdemarcation line SL1 of the branch side lane. For example, the branchlane shape estimator 134 searches for a position at which a distance inthe lateral direction (Y-axis direction) from the virtual demarcationline VL1 becomes equal to or greater than a reference value (apredetermined value) kW14 obtained by multiplying the predeterminedparameter k by the value W14 that is half the width of the lane L3, anddetermines the position to be the number-of-lanes increase startposition ISP1. The parameter k may be a fixed value or may be variablyset on the basis of the number of lanes (or the number of branch lanes)of the road RD2, a curvature of the road or lane, a distance of thebranch section RS1, and the like.

The parameter k may be set so that the reference value kW14 is greaterthan a length obtained by adding a predetermined amount (margin amount)to half the vehicle width of the host vehicle M. Therefore, in the firstembodiment, a number-of-lanes increase start position ISP1 becomes aposition at which a distance of the lateral position from the virtualdemarcation line VL1 is equal to or larger than half the vehicle widthof the host vehicle M. Thus, the number-of-lanes increase start positionISP1 is set, making it possible to set the number-of-lanes increasestart position ISP1 at an appropriate position at which the host vehicleM does not interfere with the virtual demarcation line VL1.

The branch lane shape estimator 134 derives the distance D12 in theX-axis direction from the branch section start point SP1 to thenumber-of-lanes increase start position ISP1. Since the distance D12 isa distance required for the host vehicle M to laterally move from thecurrent position to the number-of-lanes increase start position ISP1,the distance D12 may be adjusted to a predetermined length or more sothat a steering amount of the host vehicle M does not become equal to orlarger than a predetermined amount (so that the amount of lateralmovement in a predetermined distance does not become equal to or largerthan a predetermined amount). Thereby, coordinates of thenumber-of-lanes increase start position ISP1 on the road RD2 arespecified. The branch lane shape estimator 134 is not limited to a casein which the branch lane includes two lanes, but may determine thenumber-of-lanes increase start position ISP1 even when the branch laneincludes one lane or three or more lanes.

When the route generator 156 generates a target trajectory for causingthe host vehicle M to travel from the current traveling lane L1 to thelane L3 or L4 in the branch section RS1, the route generator 156generates a target trajectory that passes through the number-of-lanesincrease start position ISP1 estimated by the branch lane shapeestimator 134. For example, when the host vehicle M is caused to travelfrom the lane L1 to the branch lane L4, the route generator 156generates a target trajectory TT1 in which the centroid of the hostvehicle M passes through the number-of-lanes increase start positionISP1, and which connects a position PO1 of the center CL1 of the lane L1at the branch start point SP1 to an edge position PO4 of the center CL4of the lane L4.

In this case, the route generator 156 forms a target trajectory TT1 sothat the target trajectory TT1 passes through a position laterally (theY-axis direction shown in FIG. 6 ) offset by a predetermined distance afrom the outermost demarcation line SL1 of the branch section RS1. α isa value that is set so that a degree of interference between the hostvehicle M and the outermost demarcation line SL1 is reduced, and is thereference value kW14, for example.

When the host vehicle M is caused to travel from the lane L1 to thebranch lane L3, the route generator 156 generates a target trajectoryTT2 in which the centroid of the host vehicle M passes through thenumber-of-lanes increase start position ISP1, and which connects theposition PO1 to an edge position PO3 of the center CL3 of the lane L3.Although the target trajectories TT1 and TT2 are shown as lineartrajectories in the example of FIG. 6 , a target trajectory that is atleast partially non-linear (curved) may be generated such that asteering amount (the amount of change in a lateral position of the hostvehicle M) is equal to or smaller than the threshold. This makes itpossible to generate the target trajectory so that a degree ofinterference with the demarcation line (the virtual demarcation line VL1in the example of FIG. 6 ) that demarcates the branch lane side and themain lane side is reduced when the host vehicle M moves to the branchlane side.

The route generator 156 may generate a target trajectory from theposition PO1 to the number-of-lanes increase start position ISP1 as acommon target trajectory regardless of which lane the vehicle travels inamong the plurality of branch lanes, and generate a residual targettrajectory according to the branch lane in which the host vehicle Mtravels after reaching the number-of-lanes increase start position ISP1.In this case, the number-of-lanes increase start position ISP1 becomes abranch point of the target trajectory directed to the branch lane. Thus,the number-of-lanes increase start position ISP1 is determined, makingit possible to suppress interference between the host vehicle M and thedemarcation line to reduce discomfort felt by the occupants, to generatea more appropriate target trajectory, and to execute driving controlalong the target trajectory even when the number of a plurality of laneshas increased due to a branch.

The recommendation start determiner 142 may perform a notification forprompting the occupant of the host vehicle M to perform lane change at apredetermined timing when the host vehicle M is traveling in the lane L1and a course to the destination direction is the branch lanes L3 and L4.The predetermined timing is, for example, a timing when the distance D1from the position of the host vehicle M to the number-of-lanes increasestart position ISP1 becomes smaller than a threshold. The recommendationstart determiner 142 outputs the control information for causing the HMI30 to perform a predetermined notification to the HMI controller 170when performing the notification for prompting the occupant to performlane change. The HMI controller 170 causes a notification for promptinglane change to the branch lane (the lane L3 or the lane L4) to be outputto the HMI 30 on the basis of the control information. Thereafter, whenan instruction to change lanes in a branch lane direction is received byan operation with respect to the blinker switch 36 or the like from theoccupant, the blinker lighting start determiner 144 starts lighting ofthe blinkers of the host vehicle M on the branch lane direction side(left side in the figure).

The speed adjuster 152 performs speed adjustment for performing lanechange on the basis of the shape of the branch section, the shape of thebranch lane, the number-of-lanes increase start position, and the like.The lateral movement adjuster 154 adjusts the steering amount of thehost vehicle M on the basis of the virtual demarcation line VL1, thedemarcation line LR on the main lane side, the number-of-lanes increasestart position, and a distance from the position of the host vehicle Mto the number-of-lanes increase start position or the branch section endpoint. Accordingly, the driving controller executes driving control ofthe host vehicle M so that the host vehicle M travels along the targettrajectory TT1 or TT2. Which of the target trajectories TT1 and TT2 thehost vehicle M travels along may be set on the basis of, for example,destination information set by the navigation device 50 and the positionof the host vehicle M, may be set on the basis of an instruction (ablinker operation) by the occupant, or may be set on the basis of acongestion situation of each of the lanes L3 and L4, the speed of thehost vehicle M, and the like.

[Processing Flow (First Embodiment)]

Next, a flow of processing executed by the automated driving controldevice 100 of the first embodiment will be described. Hereinafter,driving control processing including processing of generating the targettrajectory mainly on the basis of the setting of the virtual demarcationline and an estimation result of the branch lane shape among theprocessing executed by the automated driving control device 100 will bemainly described. The processing of this flowchart may be repeatedlyexecuted at predetermined timings, for example.

FIG. 7 is a flowchart showing an example of a flow of driving controlprocessing executed by the automated driving control device 100 of thefirst embodiment. The processing shown in FIG. 7 is also processing thatis executed in second and third embodiments, which will be describedlater. In the example of FIG. 7 , it is assumed that the host vehicle Mis traveling on the main lane through automated driving. In the exampleof FIG. 7 , the recognizer 130 recognizes the surroundings situation ofthe host vehicle M (step S100), and determines whether or not there isthe branch section within the predetermined distance in the travelingdirection of the host vehicle M (step S110). When a determination ismade that there is a branch section, the virtual demarcation line setter132 determines whether or not a demarcation line demarcating the mainlane and the branch lane is recognized (step S120). When a determinationis made that the demarcation line is not recognized, the virtualdemarcation line setter 132 acquires a start point and an end point ofthe branch section (step S130), and sets a virtual demarcation lineconnecting the acquired start and end points (step S132). Next, thebranch lane shape estimator 134 estimates the number, a shape, or thelike of the branch lanes on the basis of the recognition result of therecognizer 130 or the map information (step S140). In the processing ofstep S120, when a determination is made that the demarcation line thatdemarcates the main lane and the branch lane has been recognized, theposition information of the demarcation line is acquired (step S150).

After the processing of step S140 or step S150, the automated drivingcontrol device 100 determines, for example, whether or not the hostvehicle M travels in the branch lane present ahead of the branch sectionon the basis of the destination information set by the navigation device50 and the position of the host vehicle M (step S160). In the processingof step S160, a determination may be made as to whether or not the hostvehicle M travels in the branch lane depending on whether or not a lanechange intention of the occupant has been received by an operation withrespect to the blinker switch 36, the HMI 30, or the like by theoccupant, instead of the destination information set by the navigationdevice 50.

When a determination is made that the host vehicle M travels in thebranch lane, the branch lane shape estimator 134, for example, generatesa target trajectory on the basis of the virtual demarcation line set bythe processing of step S132, the branch lane shape estimated by theprocessing of step S140, or the demarcation line acquired by theprocessing of S150 (step S170). When a determination is made in theprocessing of step S110 that there is no branch section, or when adetermination is made in the processing of step S160 that the hostvehicle M does not travel in the branch lane, the target trajectory isgenerated on the basis of the demarcation line of the current travelinglane (step S180). After the processing of step S170 or step S180, thesecond controller 160 causes the host vehicle M to travel along thegenerated target trajectory (step S190). Thus, the processing of thisflowchart ends.

[Step S140: Estimation of Branch Lane Shape]

Next, branch lane shape estimation processing shown in steps S160 andS170 in the processing shown in FIG. 7 will be specifically described.FIG. 8 is a flowchart showing an example of a branch lane shapeestimation process according to the first embodiment. In the example ofFIG. 8 , the branch lane shape estimator 134 determines a shape or typeof the branch section obtained from the recognition result of therecognizer 130 or the map information, and a start position (branch edgeposition) of each of one or more branch lanes present ahead of thebranch section (step S141A). Next, the branch lane shape estimator 134estimates a shape of a demarcation line of an outermost branch lane (anoutermost demarcation line shape) among the branch lanes (step S141B).

Next, the branch lane shape estimator 134 searches for thenumber-of-lanes increase start position in the branch section (stepS141C). Next, the branch lane shape estimator 134 sets the center lineof the traveling lane of the host vehicle M on the basis of therecognition result of the recognizer 130 or the map information (stepS141D). Accordingly, the flowchart ends. The action plan generator 150regards the center of the lane as an ideal travel route at which thetarget trajectory aims, and generates a target trajectory that passesthrough the number-of-lanes increase start position from the currentposition of the host vehicle M and travels in the branch lane in whichthe host vehicle M travels, on the basis of the above-describedoutermost demarcation line, the demarcation line (the virtualdemarcation line) that demarcates the main lane and the branch lane,information on the center line of the traveling lane, and the like.

According to the first embodiment described above, it is possible to seta more appropriate virtual demarcation line even when the demarcationline that demarcates the main lane side and the branch lane side in thebranch section cannot be recognized, and it is possible to performdriving control in which discomfort given to the occupants is reducedeven when the host vehicle M travels in the main lane and even whencourse change (lane change) to the branch lane side is performed.According to the first embodiment, when there are a plurality of branchsection end points, a virtual demarcation line corresponding to each endpoint is set, making it possible to cause the host vehicle M to travelalong a more appropriate target trajectory even when the host vehicle Mtravels in the main lane or even when the host vehicle M performs coursechange to the branch lane. According to the first embodiment, it ispossible to generate the target trajectory (traveling route) of the hostvehicle M so that the degree of interference with the demarcation lineis reduced. Therefore, it is possible to perform more appropriatedriving control on the host vehicle M.

Second Embodiment

Next, a second embodiment of the vehicle control device will bedescribed. The second embodiment differs from the first embodiment inthe method of searching for the number-of-lanes increase start positionin the branch section. Specifically, the second embodiment differs fromthe first embodiment in that, in the first embodiment, thenumber-of-lanes increase start position is searched for on the basis ofthe vehicle width of the host vehicle M and the width of the branch lanefrom the side of the branch section start point SP1 (the host vehicle M)toward the branch lane, whereas in the second embodiment, thenumber-of-lanes increase start position is searched for on the basis ofa width of the branch section from the branch lane side toward thebranch section start point SP1 side. Therefore, the followingdescription will focus mainly on the differences, and other descriptionswill be omitted. Since a configuration of the vehicle system 1 similarto that of the first embodiment can be applied to the second embodiment,the configuration of the vehicle system 1 described above will be usedin the following description.

FIG. 9 is a diagram for describing a method of searching for anumber-of-lanes increase start position ISP2 of the branch lane in thesecond embodiment. The example of FIG. 9 shows a road RD3 having mainlanes L1 and L2 and two branch lanes L5 and L6. In the example of FIG. 9, it is assumed that there are one branch section start point SP1 andtwo branch section end points EP1 and EP2, and the virtual demarcationline VL1 linearly connecting the branch section start point SP1 to thebranch section end point EP1 and the virtual demarcation line VL2linearly connecting the branch section start point SP1 to the branchsection end point EP2 are set by the virtual demarcation line setter132. In the example of FIG. 9 , it is assumed that, in the branchsection RS2, a width of the road from the branch section start point SP1gradually increases (becomes longer or larger) toward the branch laneside. In the example of FIG. 9 , it is assumed that the host vehicle Mis traveling in the lane L1 at the speed VM toward the branch sectionRS2.

For example, when there is no demarcation line that demarcates thebranch lanes L5 and L6 in the branch section RS2 shown in FIG. 9 , andwhen the target trajectories (the centers of the branch lanes L5 and L6)interfere unnecessarily (the target trajectories are close to each otherwithin a predetermined distance) even in a case in which the hostvehicle M is caused to travel in any one of a plurality of branch lanesL5 and L6 running in parallel, the occupant or a surrounding vehiclecannot specify which branch lane the host vehicle M is directed to, theoccupant is made anxious, and smooth traveling cannot be performed insome cases. Therefore, in the second embodiment, when thenumber-of-lanes increase start position is searched for, thenumber-of-lanes increase start position at which a degree ofinterference between the target trajectories (between centers of thebranch lanes) becomes small, in addition to interference between thetarget trajectory and the demarcation line being reduced, is searchedfor.

In the second embodiment, the number-of-lanes increase position searcher134 a searches for a position satisfying a predetermined condition froma position with a maximum width Wmax of the road in the branch sectionRS2 toward the branch section start point (or a host vehicle M sidedirection). The maximum width Wmax of the road indicates, for example,that widths of the demarcation line (the virtual demarcation line VL2 inthe example of FIG. 9 ) on the branch lane side among the demarcationlines (the virtual demarcation lines VL1 and VL2 in the example of FIG.9 ) that demarcate the main lane side and the branch lane side, and theoutermost demarcation line SL2 are maximized. In the example of FIG. 9 ,a straight line connecting the branch section end point EP2 to theoutermost demarcation line SL2 through a branch edge position BP2 of ademarcation line BL2 demarcating the lanes L5 and L6 is the maximumwidth Wmax of the road. Therefore, the number-of-lanes increase positionsearcher 134 a searches for the position satisfying the predeterminedcondition from this position toward the branch section start point SP1,and determines the position satisfying the predetermined condition to bethe number-of-lanes increase start position ISP2.

Here, the predetermined condition is, for example, a position at which awidth Wi between a target trajectory TT3 connecting an edge position PO6of a center CL6 of the outermost lane (the lane L6 shown in FIG. 9 )among the plurality of branch lanes (the lanes L5 and L6 shown in FIG. 9) to the position PO1 and the virtual demarcation line VL2 is equal toor smaller than a predetermined value. The target trajectory TT3 is, forexample, a trajectory that is generated along a position (including apredetermined margin (acceptable range)) at which a lateral distancefrom the outermost demarcation line SL2 becomes a length Wh6 that ishalf the width of the lane L6 on the basis of a shape of the outermostdemarcation line SL2 (a shape of the branch section RS), and isgenerated by the route generator 156. The predetermined value is, forexample, a length Wh5 that is half the width of the lane L5 that isclosest to the main lane among the plurality of branch lanes (the lanesL5 and L6) (the lane L5 that is not a target branch lane for which thetarget trajectory TT3 has been generated among the plurality of branchlanes). The number-of-lanes increase start position ISP2 is determinedunder the above-described condition, making it possible for the hostvehicle M to travel to the branch edge position (the start position ofthe branch lane) while reducing the degree of interference with thevirtual demarcation line VL2 or the outermost demarcation line SL2 andreducing the degree of interference between the target trajectories upto the respective branch lane after passing through the number-of-lanesincrease start position ISP2.

After the number-of-lanes increase position searcher 134 a determinesthe number-of-lanes increase start position ISP2, the route generator156 generates a target trajectory TT4 for causing the host vehicle M totravel in the lane L5 from the lane L1 in the branch section RS2. Inthis case, the route generator 156 generates the target trajectory TT4in which the centroid of the host vehicle M passes through the positionPO1 and the number-of-lanes increase start position ISP2 and then passesthrough a start position PO5 of a center line CL5 of the lane L5.

The route generator 156 may generate the target trajectory from theposition PO1 to the number-of-lanes increase start position ISP2 as acommon target trajectory regardless of which lane the vehicle travels toamong the plurality of branch lanes, and generate a remaining targettrajectory according to the branch lane in which the host vehicle Mtravels after reaching the number-of-lanes increase start position ISP2.In this case, the number-of-lanes increase start position ISP2 becomes abranch point of the target trajectory directed to the branch lane.

The driving controller executes driving control of the host vehicle M sothat the host vehicle M travels along the target trajectory TT3 or TT4.Which one of the target trajectories TT3 and TT4 the host vehicle Mtravels along may be set, for example, on the basis of the destinationinformation set by the navigation device 50 and the position of the hostvehicle M, may be set on the basis of an instruction (a blinkeroperation) by the occupant, or may be set on the basis of a congestionsituation of each of the lanes L5 and L6, the speed of the host vehicleM, and the like.

[Processing Flow (Second Embodiment)]

FIG. 10 is a flowchart showing an example of branch lane shapeestimation processing in a second embodiment.

In the processing of FIG. 10 , the branch lane shape estimator 134determines a shape or type of the branch section obtained from therecognition result of the recognizer 130 or the map information, and astart position (branch edge position) of each of a plurality of branchlanes present ahead of the branch section (step S142A). Next, the branchlane shape estimator 134 determines a point at which a width of the roadin the branch section is maximized (step S142B). In the processing ofstep S142B, the branch lane shape estimator 134, for example, sets thebranch edge position as a point at which the width is largest. Next, theaction plan generator 150 generates a target trajectory from a center ofthe traveling lane at a start point of the branch section to a center ofthe edge position of the outermost branch lane among the plurality ofbranch lanes on the basis of, for example, the shape of the outermostdemarcation line SL2 estimated by the branch lane shape estimator 134(step S142C).

Next, the branch lane shape estimator 134 searches for a position atwhich a distance between the target trajectory toward the branch sectionstart point from a point at which the width is maximized and thedemarcation line demarcating the main lane side and the branch lane sidesatisfies the predetermined condition (step S142D), and determines theposition (search position) satisfying the predetermined condition, whichhas been searched for, to be the number-of-lanes increase start position(step S142E). Next, the branch lane shape estimator 134 sets the centerline of the traveling lane of the host vehicle M on the basis of therecognition result of the recognizer 130 or the map information (stepS142F). Thus, the processing of this flowchart ends. The action plangenerator 150 generates a target trajectory that passes through thenumber-of-lanes increase start position from the current position of thehost vehicle M and travels in the branch lane, with the center of thelane being the ideal travel route at which the target trajectory aims.

According to the second embodiment described above, when a plurality ofbranch lanes are present after the branch section, search is performedin a direction of the start point of the branch section from the pointat which the width of the road in the branch section becomes a maximumwidth (Wmax), and the number-of-lanes increase start position ISP2 isset so that a degree of interference between the target trajectories(center lines of the branch lanes) is reduced, making it possible forthe occupant or surrounding vehicles to easily recognize which branchlane the host vehicle is directed to, in addition to achievement of thesame effect as those in the first embodiment. This makes it possible tomake the occupants feel safer, and to suppress occurrence of trafficcongestion due to a behavior of the host vehicle M in the branchsection.

Third Embodiment

Next, a third embodiment of the vehicle control device will bedescribed. The third embodiment is different from the first and secondembodiments in that the number-of-lanes increase position searcher 134 adetermines a position at which an increase in the number of lanes ends(the number-of-lanes increase end position), instead of determining thenumber-of-lanes increase start position. Further, the third embodimentis different in that the target trajectory is generated so that a coursechange to the branch lane in which the host vehicle M travels until thehost vehicle M reaches the determined number-of-lanes increase endposition is completed. Therefore, the following description will focusmainly on the above differences, and other descriptions will be omitted.Since the configuration of the vehicle system 1 similar to that of thefirst embodiment can be applied to the third embodiment, theconfiguration of the vehicle system 1 described above will be used inthe following description.

In the third embodiment, the number-of-lanes increase position searcher134 a has a different search direction or search conditions for thenumber-of-lanes increase end position depending on a road shape in thebranch section. Therefore, a method of determining the number-of-lanesincrease end position for each road shape pattern will be describedhereinafter.

<First Road Shape Pattern>

FIG. 11 is a diagram for describing a method of determining thenumber-of-lanes increase end position in a first road shape pattern. Anexample of FIG. 11 shows a road RD4 having main lanes L1 and L2 and twobranch lanes L7 and L8. In the example of FIG. 11 , it is assumed thatthere are one branch section start point SP1 and two branch section endpoints EP1 and EP2, and the virtual demarcation line VL1 linearlyconnecting the branch section start point SP1 to the branch section endpoint EP1 and the virtual demarcation line VL2 linearly connecting thebranch section start point SP1 to the branch section end point EP2 areset by the virtual demarcation line setter 132. Further, it is assumedin the example of FIG. 11 that the branch section end points EP1 and EP2are hard noses, and a soft nose SN is present ahead of the branchsection end points EP1 and EP2 (on the branch section start point SP1side or on the host vehicle M side). A zebra zone ZZ1 is provided in aregion from the soft nose SN to the branch section end points EP1 andEP2. In the example of FIG. 11 , it is assumed that the host vehicle Mis traveling in the lane L1 at the speed VM toward the branch section.

Here, the first road shape pattern is a road shape in which a searchstart position SSP of the number-of-lanes increase end position ispresent on the branch section start point SP1 side (the host vehicle Mside) rather than the road position BSP at which there is an edge(branch edge position) BP3 of a demarcation line BL3 that demarcates thelanes L7 and L8. The search start position SSP is, for example, astraight line parallel to a straight line passing through the branchsection end point EP2 on the branch lane side and the branch edgeposition BP3 (a straight line in the lateral width direction of thebranch lane), which is a point passing through the soft nose SN. In thecase of the first road shape pattern, the number-of-lanes increaseposition searcher 134 a searches for a point at which a distance (roadwidth) Wi from an outermost demarcation line SL3 estimated by the branchlane shape estimator 134 to the virtual demarcation line VL2 on thebranch lane side satisfies a first condition toward a road position BSPdirection in which there is the branch edge position BP3 (a directionindicated by an arrow A1 in the figure) from the search start positionSSP, and determines the point at which the distance satisfies the firstcondition to be the number-of-lanes increase end position.

Here, the first condition is, for example, that the road width Wi iswithin a predetermined error range with respect to a road width Wend atthe road position BSP of the branch edge position BP3, and for example,a condition “0.9Wend<Wi<1.1Wend” is satisfied. The numerical values arenot limited to 0.9 and 1.1, and may be set variably on the basis of, forexample, the shape of the road and the number of lanes.

FIG. 12 is a diagram for describing a number-of-lanes increase endposition IEP1 determined in the first road shape pattern. In the exampleof FIG. 12 , the vicinity of the number-of-lanes increase end positionIEP1 in FIG. 11 is shown in an enlarged manner. The number-of-lanesincrease position searcher 134 a extends the demarcation line BL3 fromthe branch edge position BP3 toward the branch section start point SP1,and determines a position overlapping the point at which the road widthWi satisfies the first condition, to be the number-of-lanes increase endposition IEP1. The number-of-lanes increase position searcher 134 a setsa virtual demarcation line VL3 that connects the branch edge positionBP3 to the number-of-lanes increase end position IEP1. Thenumber-of-lanes increase position searcher 134 a may extend each of acenter CL7 of the lane L7 and a center CL8 of the lane L8 to thenumber-of-lanes increase end position IEP1.

After the number-of-lanes increase position searcher 134 a determinesthe number-of-lanes increase end position IEP1, the route generator 156generates a target trajectory for causing the host vehicle M to travelin the lane L7 or L8 from the lane L1. In this case, the route generator156 generates the target trajectory so that the host vehicle M travelsat a center of the lane L7 or L8 when the host vehicle M has reached thenumber-of-lanes increase end position IEP1.

Thus, in the first road shape pattern, since the number-of-lanesincrease end position IEP1 is set on the branch section start positionside rather than the branch edge position BP3, it is possible toposition the host vehicle M faster at the center position of the branchlane. Therefore, it is possible for the occupant or surrounding vehiclesto more rapidly ascertain the lane in which the host vehicle M travels.Although the example in which the width of the road gradually increaseshas been shown in FIGS. 11 and 12 , the number-of-lanes increase endposition IEP1 is determined on the basis of the first condition, and thetarget trajectory is generated so that the host vehicle M travels at acenter of the branch lane at a point in time when the host vehicle M hasreached the number-of-lanes increase end position IEP1, making itpossible to execute more appropriate driving control, as in the case inwhich the width of the road gradually decreases.

<Second Road Shape Pattern>

FIG. 13 is a diagram for describing a method of determining thenumber-of-lanes increase end position in a second road shape pattern. Anexample of FIG. 13 shows a road RD5 having main lanes L1 and L2 and twobranch lanes L9 and L10. In the example of FIG. 13 , it is assumed thatthere are one branch section start point SP1 and the soft nose SN, andthe virtual demarcation line setter 132 sets the virtual demarcationline VL1 that linearly connects the branch section start point SP1 tothe soft nose SN. A branch section end point may be used instead of thesoft nose SN. In the example of FIG. 13 , it is assumed that the hostvehicle M is traveling along the lane L1 at the speed VM toward thebranch section.

Here, the second road shape pattern is a road shape in which an edge(branch edge position) BP4 of a demarcation line BL4 that demarcates thelanes L9 and L10 is present on the branch section start point SP1 side(host vehicle M side) rather than the soft nose SN. In this case, sincea position of the soft nose SN satisfies the first condition, thenumber-of-lanes increase end position IEP1 is set on the inner side withrespect to the current branch edge position BP4 when viewed from thehost vehicle M. Therefore, in the case of the second road shape patternas shown in FIG. 13 , the road position BSP at which there is the branchedge position BP4 is set as the search start position SSP, a point atwhich a distance (road width) Wi from an outermost demarcation line SL4estimated by the branch lane shape estimator 134 to the virtualdemarcation line VL1, from the search start position SSP toward thebranch section start point SP1 (a direction indicated an arrow A2 in thefigure), satisfies a second condition is searched for, and the point atwhich the distance satisfies the condition is determined to be thenumber-of-lanes increase end position.

Here, the second condition is, for example, that the road width Wiexceeds a predetermined error range with respect to a road width Wend atthe road position BSP of the branch edge position BP4, and for example,a condition “Wi<0.9Wend or Wi>1.1Wend” is satisfied. The numericalvalues are not limited to 0.9 and 1.1, and may be set variably on thebasis of, for example, the shape of the road and the number of lanes. Inthe example of FIG. 13 , since the width of the road gradually decreasesfrom the road position BSP toward the branch section start point SP1 (adirection indicated by an arrow A2 in the figure), a position satisfyingthe search result “Wi<0.9Wend” is determined as the number-of-lanesincrease end position IEP1. When the width of the road graduallyincreases from the road position BSP toward the branch section startpoint SP1, a position satisfying “Wi>1.1Wend” is determined as thenumber-of-lanes increase end position IEP1.

The number-of-lanes increase position searcher 134 a sets a virtualdemarcation line VL4 that connects the branch edge position BP4 to thenumber-of-lanes increase end position IEP1. The number-of-lanes increaseposition searcher 134 a may extend each of a center line CL9 of the laneL9 and a center line CL10 of the lane L10 to the number-of-lanesincrease end position IEP1.

After the number-of-lanes increase position searcher 134 a determinesthe number-of-lanes increase end position IEP1, the route generator 156generates a target trajectory for causing the host vehicle M to travelin the lane L9 or L10 from the lane L1. In this case, the routegenerator 156 generates the target trajectory so that the host vehicle Mtravels at a center of the lane L9 or L10 when the host vehicle M hasreached the number-of-lanes increase end position IEP1.

Thus, even in the second road shape pattern, since the number-of-lanesincrease end position IEP1 is set on the branch section start positionside rather than the branch edge position BP4, it is possible toposition the host vehicle M faster at the center position of the branchlane.

Even in the case of road shape patterns other than the first and secondroad shape patterns, search from the search start position SSP isperformed on the basis of the first condition and the second conditiondescribed above and the search direction, making it possible to set thenumber-of-lanes increase end position IEP1 at a position before thebranch edge position BP4. In the third embodiment, the number-of-lanesincrease position searcher 134 a may change the search direction orconditions depending on which position is set as the search startposition SSP. The number-of-lanes increase position searcher 134 a, forexample, may perform search using the second condition when there is noposition satisfying the first condition in the search in the searchdirection, or conversely, may perform search using the first conditionwhen there is no position satisfying the second condition.

[Processing Flow (Third Embodiment)]

FIG. 14 is a flowchart showing an example of branch lane shapeestimation processing in a third embodiment.

In the processing of FIG. 14 , the branch lane shape estimator 134determines start positions (branch edge positions) of a plurality ofbranch lanes and the search start position (step S143A). Next, branchlane shape estimator 134 searches for the number-of-lanes increase endposition on the basis of the search direction and conditions (the firstcondition or the second condition) depending on the road shape in thebranch section (step S143B). Next, the branch lane shape estimator 134sets the virtual demarcation line obtained by extending the demarcationline of the branch lane to the number-of-lanes increase end position(step S143C). Next, the branch lane shape estimator 134 sets the centerline of the traveling lane of the host vehicle M on the basis of therecognition result of the recognizer 130 or the map information (stepS143D). Thus, the processing of this flowchart ends. The action plangenerator 150 regards the center of the lane as the ideal travel routeat which the target trajectory aims, and generates a target trajectorythat travels at the center of the branch lane from the current positionof the host vehicle M to the edge (the number-of-lanes increase endposition) of the virtual demarcation line.

According to the third embodiment described above, the number-of-lanesincrease end position is set on the branch section start point siderather than the branch edge position, and the target trajectory isgenerated so that the host vehicle M can travel in the center of thebranch lane at a point in time when the host vehicle M reaches the setnumber-of-lanes increase end position, making it possible for theoccupant or surrounding vehicles to easily ascertain the branch lane inwhich the host vehicle M travels in the branch section, in addition toachievement of the same effects as the first embodiment. According tothe third embodiment, it is possible to further reduce interferencebetween the target trajectories to the respective branch lanes, as inthe second embodiment.

Modification Example

Each of the first to third embodiments described above may be acombination with some or all of other embodiments. For example, forschemes for determining the number-of-lanes increase start position inthe first embodiment and the second embodiment, for example, any one ofthe determination schemes may be selectively switched depending on theroad shape in the branch section, the number of branch lanes, and thelike to determine the number-of-lanes increase start position, and acenter position (average value) of number-of-lanes increase startpositions obtained by the respective determination schemes may be usedas a final number-of-lanes increase start position.

The first or second embodiment may be combined with the third embodimentto determine the number-of-lanes increase start position and thenumber-of-lanes increase end position and generate a target trajectoryto the branch lane in the branch section on the basis of the respectivedetermined positions. In this case, the action plan generator 150 maygenerate, for example, the target trajectory on the basis of a positionwhose predetermined priority is high between the determinednumber-of-lanes increase start position and the number-of-lanes increaseend position. This makes it possible to cause the host vehicle M totravel along a more appropriate route in the branch section.

In the embodiment, the recommendation start determiner 142 may cause theHMI controller 170 to inquire of the occupant at a predetermined timingabout whether or not the target trajectory based on the number-of-lanesincrease start position or the number-of-lanes increase end position isto be generated. In this case, the action plan generator 150 maygenerate the target trajectory on the basis of an inquiry result. Thismakes it possible to cause the host vehicle M to travel along thetrajectory desired by the occupant, and to further reduce discomfortfelt by the occupant.

The embodiment described above can be expressed as follows.

A vehicle control device includes

-   -   a storage medium that stores computer-readable instructions; and    -   a processor connected to the storage medium,    -   wherein the processor executes the computer-readable        instructions to:    -   recognize a surroundings situation of a host vehicle on the        basis of information obtained from at least one of a detection        device and map information;    -   generate a target trajectory for the host vehicle on the basis        of a recognition result, and execute driving control for        controlling one or both of speed and steering of the host        vehicle so that the host vehicle travels along the generated        target trajectory;    -   search for, in a branch section in which a main lane and a        plurality of branch lanes are connected, a number-of-lanes        increase end position satisfying a predetermined condition on        the start position side of the branch section, rather than an        end position of the branch section; and    -   generate the target trajectory so that course change to the        branch lane is completed until the host vehicle reaches the        number-of-lanes increase end position.

Although the embodiments for carrying out the present invention havebeen described above using the embodiments, the present invention is notlimited to these embodiments and various modifications and substitutionscan be made without departing from the gist of the present invention.

What is claimed is:
 1. A vehicle control device comprising: a recognizerconfigured to recognize a surroundings situation of a host vehicle onthe basis of information obtained from at least one of a detectiondevice and map information; and a driving controller configured togenerate a target trajectory for the host vehicle on the basis of arecognition result of the recognizer, and control one or both of speedand steering of the host vehicle so that the host vehicle travels alongthe generated target trajectory, wherein the recognizer searches for, ina branch section in which a main lane and a plurality of branch lanesare connected, a number-of-lanes increase end position satisfying apredetermined condition on the start position side of the branchsection, rather than an end position of the branch section, and thedriving controller generates the target trajectory so that course changeto the branch lane is completed until the host vehicle reaches thenumber-of-lanes increase end position.
 2. The vehicle control deviceaccording to claim 1, wherein the recognizer makes a search directionfor the number-of-lanes increase end position and the predeterminedcondition different, on the basis of a search start position at which asearch for the number-of-lanes increase end position starts and an edgeposition of the branch lane connected to the branch section.
 3. Thevehicle control device according to claim 2, wherein, when the edgeposition of the branch lane is a position at which a road width in thebranch section is maximized, and the search start position is on thestart position side of the branch section rather than the edge positionof the branch lane, the recognizer searches for a number-of-lanesincrease end position toward the edge position of the branch lane fromthe search start position, and sets a position at which a road width iswithin a predetermined error range with respect to the road width as thenumber-of-lanes increase end position.
 4. The vehicle control deviceaccording to claim 2, wherein, when the edge position of the branch laneis present on the start position side of the branch section rather thanthe end position of the branch section, the recognizer sets the edgeposition of the branch lane as the search start position to search forthe number-of-lanes increase end position toward the start position ofthe branch section, and sets a position at which a road width is largerthan a predetermined error range with respect to a road width at theedge position of the branch lane as the number-of-lanes increase endposition.
 5. The vehicle control device according to claim 2, whereinthe search start position is determined on the basis of a position of asoft nose in the branch section.
 6. The vehicle control device accordingto claim 1, wherein the recognizer searches for a number-of-lanesincrease start position in the branch section, and the drivingcontroller generates the target trajectory so that the target trajectorypasses through the number-of-lanes increase start position and reachesthe branch lane.
 7. The vehicle control device according to claim 6,wherein the number-of-lanes increase start position is a position atwhich a degree of interference between a demarcation line in the branchsection and the target trajectory is low.
 8. A vehicle control methodcomprising: recognizing, by a computer, a surroundings situation of ahost vehicle on the basis of information obtained from at least one of adetection device and map information; generating, by the computer, atarget trajectory for the host vehicle on the basis of a recognitionresult, and executing driving control for controlling one or both ofspeed and steering of the host vehicle so that the host vehicle travelsalong the generated target trajectory; searching for, by the computer,in a branch section in which a main lane and a plurality of branch lanesare connected, a number-of-lanes increase end position satisfying apredetermined condition on the start position side of the branchsection, rather than an end position of the branch section; andgenerating, by the computer, the target trajectory so that course changeto the branch lane is completed until the host vehicle reaches thenumber-of-lanes increase end position.
 9. A computer-readablenon-transitory storage medium having a program stored therein, theprogram causing a computer to: recognize a surroundings situation of ahost vehicle on the basis of information obtained from at least one of adetection device and map information; generate a target trajectory forthe host vehicle on the basis of a recognition result, and executedriving control for controlling one or both of speed and steering of thehost vehicle so that the host vehicle travels along the generated targettrajectory; search for, in a branch section in which a main lane and aplurality of branch lanes are connected, a number-of-lanes increase endposition satisfying a predetermined condition on the start position sideof the branch section, rather than an end position of the branchsection; and generate the target trajectory so that course change to thebranch lane is completed until the host vehicle reaches thenumber-of-lanes increase end position.